Modifying Ti-Based Gas Diffusion Layer Passivation for Polymer Electrolyte Membrane Water Electrolysis via Electrochemical Nitridation

Abstract

A gas diffusion layer represents an important element of collector and stack components used in polymer electrolyte membrane (PEM) water electrolyzers (WE). Nowadays, titanium-based gas diffusion layers (GDLs) have high stability and are frequently employed as anode GDLs, yet reliability issues emerging from passivation have limited their practical deployment. Hence, we develop an inexpensive way of producing high conductivity and corrosion resistance of Ti-based GDLs through electrochemical nitridation. The morphology and content of the nitride phase on the surface of the Ti felt GDL are efficiently regulated by adjusting reduction potential and reaction time. According to X-ray photoelectron spectroscopy studies, the modified Ti felt is coated with ammonium ions and nitrogenincorporated oxides, namely, TiN/TiO x , on the surface. The nitride surface shows a low interfacial contact resistance (ca. 1.0 mΩ cm 2 at 140 N/cm 2 ) and excellent corrosion resistance (0.920 μA cm −2 ) in the simulated PEM WE environments. The electrochemical nitridation provides an economic way to introducing N layers on the surface of the Ti-based GDL with high performance, which is very promising for efficient PEM water electrolysis.

Au-TiO2/Ti Hybrid Coating as a Liquid and Gas Diffusion Layer with Improved Performance and Stability in Proton Exchange Membrane Water Electrolyzer

“…Generally, the presence of a passivation layer on the surface of Ti felt has a great negative impact on the ICR because the passivation layer itself is non-semiconductor [ 40 , 41 ]. In order to remove the oxidized layer, the Ti felts were pretreated via pickling in hydrochloric acid to form a rough and electronic conductive Ti surface.…”

“…In the acidic and high-potential environment of PEMWE, the corrosion resistance is also an important indicator [ 16 , 41 , 42 ]. The corrosion resistance of the different samples was further evaluated in simulated PEMWE cells.…”

A brief introduction of electrode fabrication for proton exchange membrane water electrolyzers

“…Owing to the corrosive environment at the anode, the PTL typically consists of titanium at the anode. However, the protective passive layer covered on the Ti surface (oxide/hydroxide) leads to high surface contact resistance originating from its lack of electrical conductivity [75,76]. This results in loss of energy, which is exacerbated during the intensive operation at large current densities [77,78].…”

Highly Porous Iridium Thin Electrodes with Low Loading and Improved Reaction Kinetics for Hydrogen Generation in PEM Electrolyzer Cells

“…Due to its high efficiency, quick startup, compact design, and low maintenance cost, the proton exchange membrane electrolyzer cell (PEMEC) has been considered as a promising energy storage device to combine with renewable energy sources to accelerate renewable energy evolution. − However, low-cost and high-efficiency electrode fabrication is still challenging for the wide commercialization of the PEMEC, especially since the anode side is more sluggish. To date, Ir, IrO x , and IrO 2 are the state-of-the-art catalysts for anode electrodes, which are scarce and high cost.…”